Strings, Strings, Strings

I am the proud owner of 3 basses, one of which I use the heaviest gauge flatwounds because I bought em when I started playing and liked the mellower sound, I think it messed up my bass's neck, causing the neck to bend forward (from weight??). So lets learn about strings.

What are the benefits of heavier gauge// lighter gauge strings, whats your favorite strings && if i am changing the gauge of my strings how can I restring so that my bass stays with low action and no fret buzz?

also side question about my school's bass, the action is low on the first 3 frets then is high as hell on the higher frets. ot looks like a box and arrow now, is the problem the truss rod need to be tightened?
Thanks TB

that should give u some insite on set up as far as adjusting action and truss rod.
as far as strings; i would think heavier/lighter ga. strings would be a thing of preference/
feel. personally, i like a med. ga. string.... look into DR fat beams.
gl